Hydraulic brake operating mechanism



July 2, 1935. J. fsoRENsl-:N

i 'HYDRAULIC BRAKE OPERATING MECHANISM 5 Sheets-Sheet 1 Filed March 15, 1929 u l l 1 l ATTORNEY J. s'QRENsEN y 2,006,487

' HYDRAULIC BRAKE OPERATING MECHANISM July 72,; 1935.

V43- SheetsSheet A 2 1 Filed Harsh 15, 1929 I l I- l 0)] "INFNv lI5u` l I I E' Jnlininrensan [Nl/ENTOR BYQ c i z ci A TTRNEY:

July 2, 1935o J. SORENSEN HYDRAULIC BRAKE OPERATING Filed Marcnll, 1929 )lv L .MECHANISM s sheets-sheet 3 'Jahn Eljransen INVENTOR A Troie/VE Y Patented July 1935 HANISM John Sorensen, Weehawken, N. J.

Application March 15, 1929, Serial No. 347,228

16 Claims.

My invention relates to hydraulic brake operating mechanisms and is illustrated by a hydraulic brake mechanism in which the piston of the pressure cylinder is operated preferably in connection with a power actuator and. is provided with a hollow piston rod in communication with the pressure cylinder, and provided with a piston of smaller area than the pressure piston, directly connected to a physically operablel part so that pressure applied to the liquid in the pressure cylinder -by the power actuator, or by Physical force, or both, will be transmitted through said piston of smaller area to the physically operable part and by its variable reaction thereon will apprise the operator as to the power being exerted upon the brakes. My inventionalso includes controlling valve mecha-msm for the actuator operated by the relative movement of the said piston oi smaller area with respect to the said hollow piston rod, and specically a valve mechanism carried by said hollow piston rod, and including an oscillating part connected with a. toothed part or pinion engaged .by a rack connected with the -said y V piston of smaller area. y

My invention also includes the interposition of yielding means as a spring between a part connected with said piston oi smaller area, and the said hollow piston rod, so that the rst movement of the physically operable part will carry with it the said piston of smaller area, the piston connected with said hollow piston rod, and the movable part of the actuator connected therewith, until the resistance to the movement of the piston connected with the actuator equals or exceeds the initial resistance of said spring, after which the spring yields and permits the relative movenent of. the parts to operate said valve. mecha- -n sm.

My invention also comprises meansV for compoundingthe hydraulic pressure wherea higher hydraulic pressure is desired, which isA capable of being operated bythe power actuator, or directly by the physical force of the operator.

I attain these objects preferably by the means illustrated in the accompanying drawings, wherein similar parts are referred to throughout the several views by like numerals, in Which:'

Figure 1 is a horizontal section of the device.

Figure 2 is an enlarged section taken on line 2-2 of Figure 1.

Figure 3 is a diagrammatic plan of as applied to anautomobile.

Figure 4 is a partiallongitudinal lsection of a `modification of the hydraulic cylinder and a portion. of the hydraulic system.

the device (Cl. {io-54.6)

Figure 5 is an enlarged-longitudinal section of the valve mechanism.

Figure 6 is a. plan of a compound yhydraulic operating cylinder directly connected to the foot brake.

Figure 7 is a section taken on line 1-1 of Fig" ure 6.

The vehicle I, with its chassis 2Y has four wheels 3, 4, 5 and 6 which have brake mechanism herein shown as band brakes 1, 8, 9 and I0, respec- 10vv tively, each of which is connected to a suitable hydraulic brake actuating mechanism comprising a cylinder and piston II, I2,-I3 and I4, respectively, said cylinders being connected together and to the main 'hydraulic operating cylinder I9 by pipes I5, I8, I1 and I8. "y

This main cylinder I9 is connected by the pipe to a reservoir 2I provided witha cap 22 carrying an air plug 23 within whichv reservoir the .piston 24 is held against the. liquid 25 by the spring 26 and this pipe 2 0 has a pipe 21 connected thereto in any suitable way, ontaining a cock 28, said pipe 21 being provided for filling the system with liquid and the piston 24 with the spring 26 being provided for maintaining any suitable pressure upon the liquid 25 of the system.

' The main cylinder I9 has a llange 28'connected bythe bolts 30 to the actuator cylinder 3| havingy .the end 32 bolted to the cylinder by the bolts 33.

Thisend 32 is provided with a gland 34 and a pipe 35 connected to a flexible pipe 38 which .connects with the valve element 38 by thev pipe 31.

The other end 39 of the actuator has an air opening l4I) provided with an air strainer 4I and a pipe 42 connected to the exible pipe 43 which communicates lwith the valve element 38 by ythe pipe 44 and this element 38 is also provided with a pipe 45 that is connected to the manifold 46 of the engine 41.

'I'he hollow vpiston 48 which may be referred to as a piston with a hollow piston rod communieating with the cylinder, I9, slides within the cylinder I9. On the exterior portion of piston rod, 68x, of the hollow piston, 48, within the cylinder 3|, is slidably mounted the actuator piston head 49 held-against the ring 50, pinned to the hollow piston rod 48x by the pin 5I, by the spring 52,- the tension of which is regulated by means of the nuts 53 and 54.

'I'his hollow piston rod Mia: projects beyond the cylinder 3l andv carries on its outer and outside end a frame 55 which is screwed into position lthereon and held thereto by the pin 56.

This frame carries the valve box 30, see Figure 5, which is provided with two compartments 51 and 58. The compartment 51 is provided with a valve 59 having a valve stem 60 slidable within the boss 6| and the valve is normally held against its seat 62 by means of the spring 63.` In the upper part of the compartment the pipe 44 is connected as heretofore described.

The compartment 58 is directly opposite and spaced from the compartment 51 and in this compartment in alignment with the valve 59 is the valve 64 with the stem 65 slidable within the boss 66 and this valve is held against its seat 61 by means of the spring 68 and the pipel 45 connects this compartment with the engine manifold.

Between these compartments 51 and 58 is the space 69 and directly below the center of this space is a shaft 10 carrying a pinion 1| and a T shaped arm 12 pinned to the shaft by the pin 13.

The pinion 1| meshes with the rack 14 carried by a collar, 14a fixed to the piston rod 15a of a piston, 15, slidable within the bore 16 of the hollowpiston rod 48x, said rack being held in position by the pin 11 passing through the collar, 14a, and piston rod, 15a, and the end of the piston rod 15a has a link 19 pivoted thereto at 18, the other end of which is pivoted at to the foot lever 8|.

The air inlet, 40, provided with the air strainer, 4|, serves to connect the portion of the actuator cylinder in rear of the piston (at the right in Fig. 1) at all times withthe atmosphere, and

.also to supply the air admitted to the portion of the cylinder forward of 'the piston when the air inlet valve, 59, is open, which is its normal position in the released position of the parts, as shown in Fig. 1. When the valve, 59is open the forward end of the cylinder is placed in connectionwith the atmosphere through pipes 42, 43, 44, the space, 69, in the valve casing, 38, the pipe, 31, which communicates with said space, 69, and pipes, 36 and 35. The strainer, 4|, thus y prevents access of dust and dirt to either end Aof the actuator cylinder.

The foot lever is pivoted at 82 and is provided with a foot piece or pedal'03 and a 4return spring 84 for holding the lever and connected parts in the inoperative position.

Between the rack 14 and the end of the hollow piston rod 48x is a spring 93 which will carry the hollow piston 48 along with the piston rod, 15a, and piston 15 until the pressure on the liquid in the cylinder I9 is high enough to overcome the initial resistance of the spring whereupon a continued pressure of the foot lever 8| will move the piston rod, 15a, and piston, 15with respect to the hollow piston, 48, and rod 49m, causing the rack, 14, toY rotate the gear, 1|, and shifting the arm, 12, so, as to permit the valve, 59, to close under the action of its spring and t'o openvthe valve, 64.

In operation, when force is applied by the operator against the pedal 83 of the lever 8|, the piston 15 and the piston rod 15a carrying the rack 14 are moved inwardly together with the piston rodv 48m, carrying the pneumatic piston head 49 resiliently thereupon and the valve element 38 fixed to the piston rod 48x. These parts will move together until the pressure inthe main pressure cylinder |9 of the hydraulic system offers sufcient resistance to overcome spring 93 and hold the piston 40 from moving forward with the piston 15, whereupon the piston 15 ,and piston rod 15a will move with respect to the hollow piston 48 and the rack 14 will operate the valve mechanism and connectjthe vacuum `in themanifold with the actuator cylinder 3 I. This will cause the pneumatic piston' head 49 to move and apply a gradual pressure through the spring 52 to the hollow piston 48 and cause it to move forward, increasing` the pressure of the liquid in the cylinder I9. As will be readily seen such increased pressure reacts upon piston 15 and lever 8|, and transmits to the foot of the operator a reactive force proportionate to the area o! small piston 15.

If the operator stops the forward movement of the pedal the small piston 15, and its piston rod 15a, will stop and the continued movement of the actuator piston 49 and the main pressure piston 48, will effect a relative movement of the hollow piston rod, 48x, with respect to the piston rod, 15a, and cause the rack, 14, to operate the pinion, 1|, so as to close the suction valve and hold the brakes as applied. The hydraulic pressure in the main pressure cylinder will react upon the small piston, 15, and create a reactive force against the foot of the operator, which increases as the pressure on the liquid in the main cylinder increases, and must be overcome by the operator to prevent the release of the brakes, or to apply increased pressure thereto. This reaction apprises the operator of the amountof power applied to the brakes, and the physical force exerted `by the operator to overcome this reactionary force is necessarily transmitted to the brakes through small piston, 15, and the hydraulic medium. If the pedal is further 'depressed the brakes will be applied with greater pressure, and v when the full power of the actuator has been exerted, the operator can apply further physical force by further depressing the pedal, and fur-- theractuating the small piston, 15, and the operatory can apply brakes by physical force alone in case of failure of power.

It is obvious that various pressures may be placed upon the brakes so that the hydraulic braking power can be applied and released gradually and that manual power vcan be applied in addition.

Referring to Figures 6 and 7 the compound device is comprised of a cylinder 94 provided with two bosses 95 and 96 slidably holding the rod 91 and two bosses 98 and 99 slidably holding the rod The rods 91 and |00l are connected together on one end by the yoke |0I and nuts |02 and |03 which yoke carries aboss |04 holding a rod |05 pivoted 'to the link |01 bythe pivot |06 which link on the other end is pivoted toa foot lever |08 by the pivot |09.

'I'his foot lever |08 is pivoted at and has a foot piece or pedal I|2 on the other end.

'I'he opposite ends of the rods 91 and |00 are held together by the yoke Ill and nuts ||4 and |5 and to hold this yoke and its connecting parts `in the operating position, a spring I6 is provided that may be xed to the yoke piece I3 and to any suitable xed point`.

Riveted to this yoke at. ||1 is a rod |'|8 which `passes through the guiding bearing ||9screwed upona tube |20 within which the rod I8 'carries a piston `|2I provided with a gasket or packing ring |22 held thereon by the screw |24.

This tube |20 slides within the-stufng box |25 fixed to the cylinder 94 and the extreme end of the tube 'is provided with a piston or boss |26 which carries by the screws or rivets |21 the two gaskets or packing rings |20 and |29 and between this boss |26 and the box 25 is a return spring liquid |4| of the |30. The eil'ective area of the piston, 26, is much greater than that of the piston, |2|, as shown.

'I'he space |3 at the end of the tube |20 is connected by a branch pipe |32 to a T |33 which is connected by another branch pipe, |32 tov-the space |34 between the cylinder 34 and tube |20 and the other outlet of this T is -connected to a check valve |35. Each of the branch pipes, |32, is provided with a check valve, |32a,4 as shown. These check valves are free to open in a direction toward the cylinder, 04, to admit additional liquid from the reservoir, |36, when the parts are in released position, but will be closed whenever the pressure rises, in the cylinder above that in the reservoir, and thus prevent the by-passing of liquid around the piston, |26, from one end of the cylinder, 34, to the other.

The check valve |35 is connected to a reservoir |36 icarrying a piston |31 with a piston stem |38 in the cap |39 which cap holds the air plug |40 and to hold this piston against the vby the foot' will be multiplied in proportion to the respective areas of the pistons, iii and 526,'

and this increased pressure will be transmitted 'to the liquid betweenthe tube, |20, and cylinder, 34, and to the brake cylinders connectedv therewith.

1t will be seen that as the foot moves forward with the pedal, H2 (to the right in Figure 7) the pist-on, 32|, will move to the right also, while 'the piston, |26, and the tube or cylinder, |20, will move to the. left. Portions of the liquid within 'the tube, 920, will be forced into the end,

i3i, of the cylinder, 94, as the movements or" the parts progress, andthe liquidin the space,

934, will be expelled through the pipe, 543i, to the individual brake cylinders. 'When the foot releases the` pedal, the retracting spring, E30, will move the larger piston, |26, to the right, maure 7, withdrawing the liquid expelled to the brake cylinders, and releasing the brakes, and forcing the liquid in the portion, |3|, of the cylinder, 84, back into the tube, 20, thereby returning the piston, lil, to its normal position.

in Fig. il l have shown the compound device .of Figures 6 and l arranged to be substituted ier the cylinder,l i3,- so that the brakes may be applied Aeither by the foot pedal or by a power actuator, or both, as in the construction shown in Figs. 1, 2, 3 and 5. in this ligure the cylinder, i9, corresponds with the cylinder, 94, of Figs.

6 and 1, but occupies a reversed position, and the cylinder, i0, is supported upon theilange, 29, inthe same manner asthe cylinder, |9, in Fignre l. At the inner end of this cylinder/there is wiring, 85, through which slides a tu h or inner is the retracting spring located between the lnner cylinder, 86, and the outer cylinder, I3, and

system the spring |42 is probearing against the piston, 81, and corresponding4 with the spring, |30, in Figure 7. Above the cylinder, I0, is a reservoir, 2I`,-,with its piston, 24, spring, 26, and plug, 23, said reservoir being connected by branch pipes, 83, respectively, with the cylinder, I9, at 90, and with the space between the cylinder, I9, and the tube, 06, at 9|.y

the piston, |2I, of Figure '7. This piston is carried by the. hollow piston rod, 48h, communicating by a passage, 48c, with the interior of the inner tube or cylinder, 86, and in the hollow piston rod, 48h, is the piston, 15b, connected by the piston rod, |5c,`with the pedalfin the manner illustrated. The hollow piston rod, 48h, is connected with the piston of` the power actuator, indicated at 49in Figure 1, in the same manner that it is there shown, connected with the hollow piston, 48, and the' operation of the apparatus shown in Figure 1 will be the same,'when the pressure apparatus illustrated inFigure 4 is substituted for lthe cylinder, i0, of Figure 1, except that the pressure applied to the liquid within the inner tube or cylinder, 86, by the piston, l5b,and by the piston, 86a, :will be multiplied and transmitted to the liquid between the cylinder, 86, and the cylinder, i9, 'and thence by pipe, 62, to the brake cylinders, at a much greater pressure determined by the diiference in 'the effective areas of the pistons, lb and 38a, in proportion to the difference between the effective areas of the pistons, 15b and'48a, respectively, and the piston, 8l, This increase in the pressure applied either by the foot or by the power actuator, to the pressure nuid in the brake cylinder is accomplished in exactly the same manner as that previously described and with reference' to Figuresl 6 and 7.

lt will be seen that in all forms of the inven- -tion, the back pressure on the small piston, 'l5

(Figure l), lh (Figure 4) and l2| (Figure 7), will be transmitted to the pedal and will react upon the foot of the operator, so as to apprise him of the extent to which the much greater power isl being applied through the hydraulic pressure meansand thence to the hydraulic brake cylinders; It will also he seen that the power of the actuator under the control of the pedal may loe applied to the brake "cylinders, either directly as shown in Figure i, or through the pressure compounding apparatus, as shown in Figure '4, and it will also be seen that the pressure compounding apparatus may bepperated directly by the pedal, if desired, as illustratedpiston within said holl ow piston rod, a physically operable part operatively connected with the said smaller piston, a uid pressure operated power actuator comprising relatively movable parts, one of said parts being operatively connected with said hollow piston rod, controlling valve mechanism for the actuator,'and valve actuating means brought into operation bythe relative movement of said smaller piston with said hollow piston rod, the pressure within said pressure cylinder being transmitted at`all times through `said smaller piston to the physically operable said hollow piston rod, and controlling valve 'mechanism actuating means for said valve mechanism brought into operation by the relative movement of said smaller pistony with said hollow piston rod, the pressure within said pressure cylinder being: transmitted at all times through said operable part.

3. In a hydraulic brake system for automotive vehicles, the combination with hydraulic pressure means including a cylinder, a hollow pressure piston therein, and a hollow piston rod therefor communicating with the said cylinder through the hollow piston, a smaller piston in said hollow piston rod, a physically operable part operatively connected with said smaller piston, a uid pressure operated power actuator comprising a cylinder, a piston therein, operatively connected with said hollow piston rod, and controlling valve mechanism carried by said hollow piston, and including a toothed member, and a valve operating part connected therewith, a rack operatively `connected with said smaller piston and engaging said toothed member for operating the smaller piston to the physically valve mechanism by relative movement of the smaller piston with respect to said hollow piston rod, the pressure within said pressure cylinder being transmitted at all times through said smaller piston to the physically operable part.

4. In a hydraulic brake system for automotive vehicles, the combination with hydraulic pressure lmeans including a cylinder, a hollow pressure rack operatively connectedv with said smallerv piston and engaging said toothedmember for operating the valve'mechanism by relative movement of the smaller piston with respect to said hollow piston rod, the pressure within said pres- 5. In a hydraulic brake system for automotive vehicles, the combination with hydraulic pressure means including a cylinder, a hollow pressure piston therein, and a hollow piston rod therefor communicating with the said cylinder through the hollow piston, a smaller piston in said hollow piston rod, a physically operable part operatively connected with said smaller piston, a fluid pressure Aoperated power actuator comprising a cylinder, a piston therein, operatively connected with said hollow piston rod, and controlling valve mechanism, actuating means for said valve mechanism brought into operation by the relative movement 'of said smaller piston with .said hollow piston rod, and yielding means interposed between a part connected with said smaller piston and the said hollow pisto'n rod for transmitting to said hollow piston rod physical pressure applied to said smaller piston through said physically operable part, the pressure within said pressure cylinder being transmitted. at all times through said smaller piston to the physically operable part.

6. In a hydraulic brake system for automotive vehicles, the combination with hydraulic pressurev means including a cylinder, a hollow pressure piston therein, and a hollow piston rod therefor communicating with the said cylinder through the hollow piston, a smaller piston in said hollow piston rod, a physically operable part ton rod, and including a toothed member, and a I valve operating part operatively connected therewith, a rack operatively connected with said `smaller piston and engaging said toothed mem- 7. In a hydraulic brake system -for automotive vehicles, the combination with a main'pressure cylinder, a second cylinder movable longitudinally within the same and provided with a piston, said cylinders communicating with each other adjacent to one face of the piston, and a pressure outlet communicating with the space between said cylinders on the opposite face of said piston, a second piston ci?y smaller area than the main piston working in said second cylinder, a physically operable part, means for applying force to said second piston under the control of said physically operable part, said physically operable part being operatively connected with a part subjected to the fluid pressure 'insaid second cylinder operating in a direction to resist the torce applying movement of said physically operable part.

8. In a. hydraulic brake system for automotive vehicles, the combination with a main pressure cylinder, a second cylinder movable longitudinally within the same and provided with a piston, said cylinders'communicating with each other adjacent to one face of the piston, and a pressure outlet communicating with the space between said cylinders onv the opposite face of said piston, a second piston of smaller area than the main piston working in said second cylinder, a hollow pisyton rod `connected with said second piston, and

communicating with said second cylinder, a third piston in said hollow piston rod, a `fluid pressure operated power actuator having amovablepart connected with said hollow piston rod, controlling valve mechanism for said actuator operated by the relative movement between said third piston and said hollow piston rod, a physically operable part, and yoperative connections therefrpm to said third piston.

9. In a hydraulic brake system for. automotive vehicles, the combination with a main pressure cylinder, a second cylinder movable longitudinally within the same and provided with a piston, .said cylinders communicating with each other adiacent to one face of the piston, and a pressure outlet communicating with the space between said cylinders on the opposite face of said piston, a second piston of smaller area than the main piston working in said second cylinder, a hollow pis` ton rod connected with said second piston, and communicating with said second cylinder, a third piston in said hollow piston rod, a fluid pressure operated power actuator having a movable part connected with said hollow piston rod, controlling valve mechanism :for said actuator carried by said hollow piston rod, and including. a movable valve operating part, a physically operable part connected with said third piston, and a part connected with said third piston for actuating said.

valve operating part by a relative movement between said third piston and the said hollow piston rod.

10. in a brake system for automotive vehicles, a brake, brake operating means including a iluid operated brake applying motor, force transmitting connections interconnecting said brake and the power element of said motor, valve means for controlling the operation of said motor, manually operable means for operating said valve and a connection between rsaid manually operable means and saidvalve, said valve comprising. two major working parts, one of said parts being secured to the aforementioned power element of the motor and the other of said parts being interconnected with the manually operable means through the intermediary of the aforementioned connection, and means interconnecting said force transmitting connections and said last mentioned connection, said latter means serving to bothv transmit the physical effort of the operator to' apply the lbrake manually and to transmit to the manually operable member a reactive force as' the brake is being applied by power to thus apprise the operator of the degree of power operation of the brake.

11. In an automotive brake operating mecha-l nism, a pressure diierential operated motor, a fluid connection between the power element of said motor and brakes to be operated, a control element and one of vsaidvalve parts, and other .means interconnecting the other of said aforementioned valve parts, the fluid connection and the manually operable member. A

12. In a brake operating mechanism for 4auto- Anection comprising a master cylinder, a control valve for said motor comprising relatively movable parts so constructed as to provide a followup control of the servo motor, a brake control i f ling operator operated'part, means interconnecting one part of said valve and said power element, and other means positively interconnecting another part of said valve, said operator operated part and said yfluid connection, whereby the operator is aided in 'the control of the brakes both by the"followup control of the servo motor and by the reactionary force upon the operator operated member from the fluid connection as the brakes are applied by powerc 13. In a braking system employing liquid for transmitting the brake applying force, with a master cylinder having a piston movable therein for the purpose, a vacuum cylinder, a power piston movable in said vacuum cylinder, piston rod y means connecting said pistons, valve means arranged for connecting l-a source of negative fluid pressure with the vacuum cylinder, operator operated means for controlling said valve means,`

foot pedal controlling said `power device, apiston` associated with said foot pedal, and connections leading from said master cylinder'to said piston whereby the pressure exerted by said power device on the liquid in said master cylinder reacts upon said pedal. i f' 15. In a' braking system employing a liquid filled expansible chamber for applying the brak- 45 ing force, fluid-pressure responsive means associated with said expansible chamber means for producing a brakingforce upon the confined liquid, operator operated valve means for control-.

ling said, fluid-pressure-responsive means, and means to cause the brake-applying actuation of said valve means to be opposed in amounts varying with the pressure of said liquid.

16. Ina braking vsystem employing liquid for transmitting the brake applying force, with a master 'cylinder having a piston movable therein for the purpose, a vacuum cylinder, a power .piston` movable in said vacuum cylinder, means connecting said pistons whereby said master cylinder piston may be moved by said power piston to apply the brake, valve means arranged for connecting a source of negative fluid pressure with the vacuum cylinder, operator operated means for controlling said valve means, and means causing opening operation of said valve means .to be opposed in amounts varying wit the pressure of said liquid. y

Jorn: soREN's'EN. 

